I believe it's an effort to show a netsplit in the traditional form (server1, server2) without placing blame on a particular server.

Back when I IRCd regularly (and perhaps this is still the case today), certain servers would get a reputation for splitting more than others, and I think this network (and/or its ircd) decided to mask it without breaking the general format.

It's to avoid showing the server names to the public on some IRC networks for various reasons including security through (some) obscurity.